Bar codes are commonly utilized throughout the commercial and retail worlds in order to accurately determine the nature, cost and other vital data of an individual item. Bar codes, however, are purely passive constructs, and therefore cannot offer or transmit information themselves, instead relying upon known bar code readers to scan and interpret the information stored in the bar code itself. Moreover, the information content of bar codes is static, and cannot be changed or supplemented at will once the bar code is fabricated.
In recent years, differing electronic article surveillance (EAS) platforms/tags have been developed to address the shortcomings of known bar code systems. One such type of EAS is radio frequency identification (RFID) platforms/tags. RFIDs are small (typically) battery-less microchips that can be attached to consumer goods, cattle, vehicles and other objects to track their movement. RFID tags are normally passive, but are capable of transmitting data if prompted by a reader. The reader transmits electromagnetic waves that activate the RFID tag. The tag then transmits information via a predetermined radio frequency, or the like. This information is then captured and transmitted to a central database for suitable processing.
An RFID system typically is made up of a transponder, or tag, which is an integrated circuit (IC) connected to an antenna, which is then generally embedded into labels, a reader which emits an electromagnetic field from a connected antenna, and an enterprise system. The tag draws power from the reader's electromagnetic field to power the IC, and broadcasts a modulated signal which the reader picks up (via the antenna), decodes, and converts into digital information that the enterprise system uses.
There are two main types of RFID devices, including inductively coupled RFID tags, which may be UHF as are the current Gen 2 tags. Typically, there are three main parts to an inductively coupled RFID tag:                Silicon microprocessor—These chips vary in size depending on their purpose;        Metal coil—Made of copper or aluminum wire that is wound into a circular pattern on the transponder, this coil acts as the tag's antenna. The tag transmits signals to the reader, with read distance determined by the size of the coil antenna. These coil antennas can operate at many frequencies, including the UHF Gen 2 tag frequency which is currently specified as approximately 920 MHz; and        Encapsulating material—glass or polymer material that wraps around the chip and coil.        
Inductive RFID tags are powered by the magnetic field generated by the reader. The tag's antenna picks up the magnetic energy, and the tag communicates with the reader. The tag then modulates the magnetic field in order to retrieve and transmit data back to the reader. Data is transmitted back to the reader, which directs it to the host computer and/or system.
Inductive RFID tags are very expensive on a per-unit basis, costing anywhere from $1 for passive button tags to $200 for battery-powered, read-write tags. The high cost for these tags is due to the silicon, the coil antenna and the process that is needed to wind the coil around the surface of the tag.
Another type of known RFID are capacitively coupled RFID tags. These tags do away with the metal coil and use a small amount of silicon to perform that same function as an inductively coupled tag. A capacitively coupled RFID tag also has three major parts:                Silicon microprocessor—Motorola's BiStatix RFID tags use a silicon chip that is only 3 mm2. These tags can store 96 bits of information or more, which would allow for trillions of unique numbers that can be assigned to products;        Conductive carbon ink—This special ink acts as the tag's antenna. It is applied to the paper substrate through conventional printing means; and        Paper—The silicon chip is attached to printed carbon-ink electrodes on the back of a paper label, creating a low-cost, disposable tag that can be integrated on conventional product labels.        
By using conductive ink instead of metal coils, the price of capacitively coupled tags are fractions of a dollar. These tags are also more flexible than the inductively coupled tag. Capacitively coupled tags can be bent, torn or crumpled, and can still relay data to the tag reader. In contrast to the magnetic energy that powers the inductively coupled tag, capacitively coupled tags are powered by electric fields generated by the reader. The disadvantage to this kind of tag is that it has a very limited range.
While the retail industry recently settled on using UHF Gen 2 passive RFID for item level tags as a minimum, as the two preceding examples of known RFID devices indicates, there does not presently exist a generalized industry-standard RFID protocol. With different manufacturers utilizing different RFID devices on their disparate products, large department stores, warehouses and/or shipping containers often contain a plurality of differing RFID devices.
Still further, known RFID devices are designed so that they may continue to communicate with extraneous readers well after the time of initial purchase. That is, known RFID devices are designed so that tracking of an item can be accomplished from the time the item leaves the factory, until it rest within the residential dwelling of its purchaser.
The very attributes, however, of known RFID devices that permit these devices to continue to operate and communicate with a reader well after the time of initial purchase, also poses problems for closely nested commercial or retail facilities.
For example, once a purchaser buys an item at a store, the RFID device will communicate with an integrated reader at the checkout. The reader will detect and interrogate the RFID device, and thereafter permit the purchaser to exit the store without setting of an alarm for shoplifting. But because of the resilient nature of the RFID devices, these devices continue to be passively ‘active’ even if the purchaser goes into another retail establishment, as often happens in a mall or shopping center environment. Once the original purchaser leaves the second retail store, the RFID detection equipment in the second store may awaken the RFID tag, and erroneously alert the security system of the second store. This scenario is only worsened by the differing RFID devices and protocols that potentially can exist in the market.
In addition to the differing RFID technologies mentioned above, other EAS technologies exist having their own operational protocols, such as acousto-magnetic (AM) EAS circuitry. Similar to the problems noted above, the problem for, e.g., manufacturer is the uncertainty of knowing which EAS technology will be employed at various stages of the manufacture, transportation and inventory of items equipped with one of the many differing EAS technologies.
It will therefore be appreciated that the primary EAS protocols in place are the acousto-magnetic (AM) type and the RF type, as discussed above. These differing EAS protocols are each independently used by various major retailers and are currently not compatible technologies. Thus, a manufacturer/distributor must maintain separate inventories of their products for the different EAS protocols incurring the added cost in doing such a practice or the manufacturer/distributor must apply both tags/labels to each of their products incurring the added cost of this alternative practice.
With the forgoing problems and concerns in mind, it is the general object of the present invention to provide a universal tracking system that is capable of harmonizing the use of differing EAS technologies/devices by integrating more than one such technology on a common substrate/platform. More preferably, it is the general object of the present invention to provide an integrated EAS label/tag assembly, which is compatible with both AM type and RF (including RFID) systems. The invention more preferably includes the AM type transponder which is composed of one or more amorphous alloy strips with a high magnetic permeability and a magnetic biasing strip which can be cast, die cut, painted, printed, etc. The amorphous strip(s) are packaged such that they can freely resonate and is (are) sized to resonate at the desired frequency of standard AM type EAS.